The downloadable PDF presentation attached shows a case study of depth to economic basement mapping from Northern Chile using a combination of geophysical methods
It was given at on line geophysics conference in July 2021 when Mike was still with BHP
https://chilexploregroup.cl/en/latin-geophysics-explore-2021-EN/
The authors were Michael Webb, Todd Grant and Raimundo Passi
BHP kindly allowed for the presentation to be made and a PDF version to be available publicly and their help is gratefully acknowledged